In 1980, IBM developed and used the process of Separation by Implantation of Oxygen (SIMOX) to develop and manufacture SOI materials. This process needs implantation of a very high dose of oxygen ions (approximately 5×1018/cm2). Although a silicon dioxide layer is formed by high-temperature annealing and most of defects are eliminated by re-cleaning, it is still impossible to eliminate all defects caused by ion implantation. In 1992, a French research-oriented company, i.e., Commossariat Al' Energie Atomique, used a thin film transfer technology, i.e., Smart Cut, to successfully transfer a silicon single-crystal thin film to another silicon substrate. In this process, firstly, hydrogen ions are implanted into a silicon wafer that has generated an oxidation layer, and then this silicon wafer is bonded to another silicon wafer. After high-temperature annealing, the implanted hydrogen ions obtain kinetic energy and thus are polymerized into hydrogen molecules to be filled into micro-cracks. The formed hydrogen molecules cannot leave the cracks by diffusion. According to the principle of PV=nRT, the number of hydrogen molecules rapidly increases. Thus, the pressure in the cracks rises, then the micro-cracks are expanded to form a crack panel and are aggregated into a large area of crack holes, and finally, an upper layer and a lower layer of the element wafer are detached to produce a thin film, and the thin film is transferred to a substrate wafer to form an SOI structure.
Another wafer splitting way is TM (thermal microwave) wafer-splitting. The thermal microwave wafer-splitting process uses microwave radiation instead of a traditional heat source. When the silicon wafer reaches a certain temperature by absorbing microwave energy, H+ is aggregated into H2 to achieve the effect of splitting the silicon wafer. However, for the process of microwave wafer-splitting, as the silicon wafer is not heated uniformly, it is easy to cause non-uniformity of final film thickness, and the surface roughness of the SOI after wafer splitting is high.
It is urgently desirable to obtain a method for preparing an SOI wafer by using rapid thermal processing, which has an excellent technical effect.